I just received this insulator-shaped object from Mr. Yannick. It looks more like a part of a cemented multipart than a complete insulator.

Notice in the photos (shamelessly lifted from his eBay listing) that, although the top has what looks like a wire groove, it is not continuous across the top. There is a depression in the middle. And there is not a well-formed continuous groove for a wire tie.

Second, both the top and bottom have indentations that look like they were intended to prevent rotation, for example, if cemented into something else.

Finally, there are no internal threads, nor is there anything inside that could grip a cemented-in pin, as one usually sees with French insulators.

So, what is it?

-----

Once again, ICON to the rescue!

David Dahle, and Alvaro Ruedas from Spain, replied that it is a standoff insulator, missing its end caps, used to support bus bars. Alvaro sent this link: [id=83349105].

And then Karolewski Yannick, who sold it to me, furnished this link, which shows it used as a standoff for fuses: [id=237822476].

Thanks!